Lab 5 - working or conclusion PDF

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Tittle:Design a Multistage BJT Amplifier CircuitIntroduction:In Multi-stage amplifiers , the output of first stage is coupled to the input of next stage using a coupling device. These coupling devices can usually be a capacitor or a transformer. This process of joining two amplifier stages using a c...

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Tittle: Design a Multistage BJT Amplifier Circuit Introduction: In Multi-stage amplifiers, the output of first stage is coupled to the input of next stage using a coupling device. These coupling devices can usually be a capacitor or a transformer. This process of joining two amplifier stages using a coupling device can be called as Cascading. •

The advantages of the multistage amplifier are flexibility within input & output impedance and higher gain. The multistage amplifier applications are, it can be used to increase extremely weak signals to utilizable levels. The distortion can be reduced by changing the signal within stages.

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A multistage amplifier using two or more single stage common emitter emitter amplifier is called as cascaded amplifier. A multistage amplifier with common emitter as the first stage and common base as second stage is called amplifier.

Applications of Multistage Amplifier: •

The advantages of the multistage amplifier are flexibility within input & output impedance and higher gain.

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The multistage amplifier applications are, it can be used to increase extremely weak signals to utilizable levels. The distortion can be reduced by changing the signal within stages. At present, any electronic device can process digital or radio electrical signals by including a multistageamplifier.

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Whenever the amplifier is cascaded, then it is required to employ a coupling network among o/p of one amplifier as well as i/p of the multistage amplifier. This kind of coupling is also named as interstage coupling. In this amplifier, there are three multistage amplifier types are used like RC coupling, transformer coupling, and direct coupling.

Circuit Diagram:

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Figure 1 •

The power gain otherwise voltage gain can be achieved by the single-stage amplifier but it is not enough in practical application. For that, we have to use multiple stages of amplification for achieving the required voltage gain or power.

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This kind of amplifier is termed as a multistage amplifier analysis. In this amplifier, the first stage output is fed to the next stage input. Such type of connection is commonly known as cascading. This article discusses an overview of the multi-stage amplifier and its frequency response.

Simulations on proteus:

Figure 2

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Table:

𝑽𝒊𝒏 50 mV 60 mV 70 mV 80 mV 90 mV 100 mV

𝑽𝒐𝒖𝒕𝟏 1.46V 1.59V 1.74V 1.92V 2.09V 2.38V

𝑽𝒐𝒖𝒕𝟐 2.77 V 2.68V 2.73V 2.70V 2.66V 2.62V

𝑽𝒐𝒖𝒕𝟑 4.31V 4.32 V 4.34 V 4.35 V 4.37V 4.40V

• In Multi-stage amplifiers, the output of first stage is coupled to the input of next stage using a coupling

device. These coupling devices can usually be a capacitor or a transformer. This process of joining two amplifier stages using a coupling device can be called as Cascading. The following figure shows a two-stage amplifier connected in cascade.

Voltage Gain: 𝑉𝑖𝑛1 = 100mV 𝑉𝑜𝑢𝑡1=2.38V 𝑉𝑜𝑢𝑡2=2.62V 𝑉𝑜𝑢𝑡3=4.40V 𝑉𝑜𝑢𝑡 Av= 𝑉 𝑖𝑛

Av1=23.8 Av2=26.2 Av3=44 𝐴𝑣𝑡𝑜𝑡𝑎𝑙=Av1 x Av2 x Av3=27436

Multistage Amplifier Frequency Response

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The gain’s phase-shift & amplifier’s voltage gain mainly depends on the range of frequency over the operation of the amplifier. Generally, the total range of frequency can be separated into 3types like high-frequency range, mid-frequency, and low-frequency range. Generally, for the analysis of these amplifiers, we require to find out dissimilar parameters. The voltage gain of this amplifier is equivalent to the product of voltage gain result of separate stages. The current gain of this amplifier is equivalent to the product of the current gain result of separate stages Input impedance is the first stage’s impedance Output impedance is the last stage’s impedance

Waveform:

Conclusion: For learning and analyzing I conclude that the impact of input and output loading can be minimized by two amplifiers with appropriate input and output characteristics. Multistage can be used to create amplifiers with high input resistance, low output resistance and large gains A multistage amplifier using two or more single stage common emitter emitter amplifier is called as amplifier. A multistage amplifier with common emitter as the first stage and common base as second stage is called amplifier....